Using a Mass Air Flow Sensor in a Furnace

Discussion in 'Burners and their construction' started by Melterskelter, Jan 9, 2022.

  1. Melterskelter

    Melterskelter Gold Banner Member

    OK, you guys probably thinkI am slacking since I have not posted to this thread for a couple days. I have had limited time for this project as I have been very busy molding sand, cleaning and shipping castings, refining a patterns, and making aluminum flask parts.

    But, last night I did hook up the sensor to 12v and tried to find a signal either as a wave-form using my oscilloscope (I sure wish I had an oscilloscope mentor here as I am pretty green with respect to scopes) and using a VOM looking for a DC voltage signal. So far, no joy.

    The scope.
    BD328F78-5C65-4871-BCD1-87D4793424EC.jpeg

    To get air flow through the sensor , I used a home vac taped to the sensor. Seemed like a good idea.
    69BA516F-A88D-469E-8998-9F9A509DDCA6.jpeg



    Of course, I do not know for SURE that I have the right leads hooked up for power, Gnd, and signal :-(

    Wading into something like this with no clear guidelines adds to the fun.

    So, sometime today I hope to try to check out the MAF’s on my truck and Subaru to see if I can find a signal.

    Denis
     
    Last edited: Jan 13, 2022
  2. Smoking Shoe

    Smoking Shoe Copper Banner Member

    I presume that you are using a digital VOM and not an analog one?
     
  3. Melterskelter

    Melterskelter Gold Banner Member

    Yes, digital. My much-loved 1970-vintage Radio Shack analogue meter died a couple years ago.

    Denis
     
  4. I had a look around online for info about your airflow sensor and couldn't find anything definitive apart from the principle of function. I did find an Arduino board for a sensor running off the "hot wire" principle for $24 complete with sample software. It outputs a 0-3.3V voltage proportional to airflow and is capable of measuring 150 MPH wind speeds. It's not nearly as rugged as your unit but at least the circuit and function is well documented and that's worth paying for.

    https://moderndevice.com/product/wind-sensor-rev-p/

    Edit: looks like there are none in stock at present.
     
    Melterskelter likes this.

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